Lactic Acid Bacteria from Northern Thai (Lanna) Fermented Foods: A Promising Source of Probiotics with Applications in Synbiotic Formulation.

Northern Thai culture offers a rich variety of traditional fermented foods beneficial for gastrointestinal health. In this study, we characterized lactic acid bacteria (LAB) from various indigenous fermented foods as potential probiotic candidates and determined their properties for application in commercial synbiotic formulation. Five isolates demonstrating high tolerance to low pH (2.0) and 0.3% bile salts were collected and characterized. These included three strains of isolated from nham (NB1, NP2, and NP11) and two strains of isolated from pla-som (PS4 and PS7). All the selected LAB isolates exhibited γ-hemolytic activity, strong antimicrobial activity, and high resistance to gastric and duodenal digestion conditions. Among the LAB isolates, NB1 demonstrated the highest capacity for adhesion to Caco-2 cells, auto-aggregation, and antioxidant activity, differing significantly ( < 0.05) from the other isolates. Furthermore, the NB1 strain exhibited preferential growth in the presence of commercial prebiotics (fructooligosaccharide, lactose, and inulin) and good survival after lyophilization, which is a desirable characteristic for a powdered ingredient. Therefore, the NB1 strain is a suitable probiotic candidate for applications in synbiotic formulation or as a functional food ingredient.